This invention relates to a process for producing a spongy material useful for skin care and other purposes from glucomannan gel.
Glucomannan is a polysaccharide complex found in the tuber of an Amorphophallus species such as A. konjac, A. kosiana, A. shichitoensis, A. companulatus, A. variabilis and A. oncophyllus. Aqueous solutions of glucomannan produce a water-insoluble, thermally irreversible gel under alkaline conditions. This phenomenon has long been utilized in Japan and other countries for the production of "conjac", a processed food made from Amorphophallus tuber flour. It has long been known that when freezing and thawing "conjac" gels, a spongy mass or skeleton is formed by dehydration. This product is hereinafter referred to as "konjac sponge" Because of its pleasant feel to the skin, the konjac sponge is more suitable than natural sponge or polyurethane foams as materials of various skin care products such as cosmetic puffs, baby's skin cleaners and the like. However, the cellular texture of konjac sponge is not uniform and varies from coarse to fine depending upon its production conditions. In order to attain a uniform texture, the production conditions must be controlled carefully and delicately.
A need exists, therefore, for a process for producing konjac sponge having a uniform texture in terms of the pore size and shape in a cost-effective manner in the large scale production thereof.